Dental engine hand piece



Sept. 7, 1948. c, ANGELL 2,448,758

DENTAL ENGINE HANDPIECE Filed Sept. 22, 1944 v s Sheets-Sheet 1 Zmventor (Ittomeg Sept. 7, 1948. R. c. ANGELL 2,448,758

DENTAL ENGINE HANDPIECE Filed Sept. 22, 1944 s Sheets-Sheet 2 3maentor attorneg Sept. 7, 1948- R. c. ANGELL DENTAL ENGINE HANDPIEcE Patented Sept. 7, 1948 STATIE'S PATENT OFFICE laments DEN DALENGINE HANWPIECE Robert :G. Angelhrltrince Bay, RN. 1., ,assignor to .The S....S. White DentalTManufacturingrCompanyaaccrpora'tion of Pennsylvania Appiicatitm September 22, 31944, :Seria'l No. 555L245 17 Claims. (Gl..32e26.)

My ;-invention relates particularly :to that 1312155 'ofrhandpieces thatiaraadapted totheiemployedi-n -;connection rwithidentalen ines and in which the mutating parts :inolude ichuck mechanism that .-is yarnanged tovdetachablyaengageadrills, nburs, g-rindling tools, and ;-such implements as are common- .ly employed =;in the practice of dentistr .and .in iwhich the :tocl actuating .parts ,are vbelt driven .;and :the assembly is generally :known ,as an r8111- loord-ihandpiece.

Ehe principal (objects .-of any invention are =-to provide-7a,; dental engine handpi'ecehavingva slipiointconnection nbetween its operativelorldriven section and tits driving :section whereby they may he relatively separated -by :axially pulling them apart :to s-readily :f-acilitate sterilization, replacement and-substitution. 1

other objects f my rinvention are {to provide a dental rengine l-handp iece embody n a r-rgeadily separable slip ioint-struoture twith exteriorly :dis- ,posed adjusting means -.conveniently accessible ,ior -manipu1ation, whereby the itool engaging chuck may be actuated 1to engage and ..=release .said .tool.

-,My winvention comprehends a dental engine mhandpiece having .a tcomposite tool-driving =holllow .spindle comprising relatiyely separable ,aligned .connectable spindlesections .which may the axially drawn apart and replaced, but when relatively engaged :rotate ttogetherhasra .unit.

Further objects of my invention are ,to .pro

vide a slip-joint connection .between the operautive handpieceproper and the ,driving elements including the driving belt pulley and its sup- ;porting structure which remain attached :to the .wrist joint structure with the driving belt intact while the operative handpiece proper is \withdrawn, and with which supporting structure ,a straight .handpiece, angle .handpiece --or contraangle .handpiece "may be interchangeably connected .or.disconnected by an axial push or pull motion respectively with equal facility.

'The .form of my. invention as hereinafter ymore "specificallydescribed comprises adental engine handpiece having .a casing vor sheath .which .is arranged for axial engagement .with and withdrawal .Ifrom .a wrist-joint tram-e, .being retained therewith Joy a readily releasable detent latch, and which .includes a separable driven section of a composite rotary tool actuating spindle,

having means engagea'ble -with a cooperative driving spindle section mounted 'for 'rotaitionin said "frame; whereby *saidspindle sections 'are "caused to rotate together but being capable of "rela ft'ive separation by an axially directed pull 'ex- 2 lertedroppositely to withdraw said {sheath and its contained parts, when thus .released \bylsaid idetent. t

My invention also .includes all of the *various novel dentures 10f ,-construc.tion and arrangement was @hereinaiter more definitely (Specified.

In .the accompanying drawings .Eigure al is an rsiderelevatianal .view .oi ga, handpieceeconstructed ,i-naccordance-with my invention-shown attached to the wristjoint connection ,or support; Figu2 cisiaside selevational mew at the said wristfloint connection as it appears when the handpiece proper has been removed; Fig. g3 his aysideteleva- .tional view of the'athus removed handpiece per se; Figprl is .-a sideelevational :view Loi .the chuck actuating .rod which projectsttromitherri hthand end :of the handpiece illustrated :in EigMB, but shown ,asrotated lone-eighth ,turn tirom the position illustrated in said Fig. 3; Fig. 5 is an enlarged central-yertical llongitudinalfsectional view .of the handpiece structure shown {int-Fig. .1, without the .wristrioint therein illustrated, ,certain parts ,being shown .in elevation .for convenience of -.,illusttration Fig. ..6 is a transverse ertical sectional viewtakcngon the linerfi-afi in lEig. l5; Rig. 7 -is a transverse .ycrtical sectional yiew vtaken ion the line .'I--] in .Fig. 5.; 8 .is a perspective view \of vthe forward section .of the slip-i oint spindle v-ts'howniinli'ig. 5,; .Fig. 9 is [a perspective --view .01

enlarged central vertical longitudinal sectional View of a contra-angle handpiece conveniently embodying ,a rsliprjoint assembly vconstructed in accordance with my invention, "certain parts .being shown vin elevation ,for convenienceof ,illustration; Eig. 15 van .enlarged central vertical longitudinaltsectional .view of. alright-canglelhandpiece conveniently embodying a slipjoint assembly constructed in accordance with my .invention, certainlparts beings'hown in elevation for convenience of illustration; Fig; 16 is alienlarged fragmentary side elevational view (if-the rear end portion of the rear section of the chuck actuating rod shown in Figs. 3, 4 and 5; Fig. 1'7 is an enlarged front elevational view of the chuck actuating rod thumb-nut illustrated in Figs, 5, 14 and 15; and Fig. 18 is an enlarged vertical longitudinal sectional view of the thumbnut shown in Fig. 17, taken on the line |8-|8 in said figure.

In said figures, the wrist-joint frame I is provided with the hollow supporting swivel post 2 which is swivelly engaged with the wrist-joint structure 3 of well known construction, and said frame I also has the forwardly projecting flanged sleeve 5 serving as a frame hub and affording a bearing for the rearwardly disposed tool driving spindle section 6, and having its radially extending flange embedded in the countersunk recess 9 in said frame I.

The spindle section 6 is provided at its forward end with the radially extended flange I0 affording a shoulder II which bears against the forward end of the sleeve 5, and from which flange I0 forwardly extending relatively parallel jointed projections or prongs l2 extend forwardly.

Said spindle section 6 is provided near its rearnut washer H is engaged to axially retain the relatively rotatable thumb-nut IS with its threaded collar 20 in its predetermined axial position on said spindle section 6.

The structure thus described in detail represents the parts that are retained with the wristjoint mechanism and from which the handpiece proper may be readily disengaged normally for sterilizing purposes, or for substitute replacement.

The readily detachable structure of the handpiece, or what for convenience may be termed the handpiece proper, includes the base member or back sleeve block 2| which is preferably annular and provided with the rearwardly projecting pin 22 having the detent'engaging notch or depression 23 with which the cupped spring detent plunger 25 may engage and be forced to bear against its angularly directed wall to retain said block 2| in engagement with the forward face 26 of the frame Said detent plunger 25 is mounted to reciprocate in the bore 21 and is opposed by the cupped latch spring screw 29 which is screw-threadedly engaged in said bore 21 and between which and said reciprocatory detent plunger 25 is interposed the coiled expansion spring 3|] tending to force the point of the detent plunger into the notch 23 against its rearward most inclined wall.

Said back sleeve block 2| carries the forwardly extending bearing sleeve 3| which is screwthreadedly engaged therewith and which has the radially extending externally screw threaded flange 32 with which the union nut 33 may be engaged by the screw threads 35, as shown in Fig. 5,

The union nut 33 is provided with the knurled band 36 by means of which it may be conveniently rotated, and is further provided with the internal screw threads 3'! with which the relatively cooperative externally screw-threaded split bearing adjusting nut 39 may be engaged for relative axial adjustment.

With further reference to Fig. 5, the inner plane face of said adjusting nut 39 bears against the radially extending flange 4| of the casing or sheath 42 which includes the integrally joined ribbed and knurled barrel 43 and the nosepiece 44, the sheath members 42, 43 and 44 being conveniently joined by the solder joints 45 and 45 to form the integral sheath structure as illustrated.

The nosepiece 44 of the compositely formed sheath is tapered toward its forward end and affords a conoidal bearing 41 tapering toward its tool receiving aperture 49, and in which bearing the forward similarly tapered end portion 50 of the forward tool driving spindle section 5| is journaled.

Said forward tool driving spindle section 5| includes the relatively separable rearward extension 52 which is integrally joined therewith by the cooperative screw threads 53 to form said forward tool driving spindle section structure, and said rearward extension 52 is rotatably supported in the bore 55 of the bearing sleeve 3| and has the radially extending flange 56 engaging the forward end of said bearing sleeve 3| which conveniently serves as a thrust bearing 51 therefor.

As illustrated in Figs. 5 and '7, but probably best shown in Fig. 8, the rearward etxension 52 of the forward tool driving spindle section 5| is provided with the rearwardly extendin pointed projections or prongs 59 which are arranged to removably interengage with the forwardly extending pointed projections or prongs 12 on the rear spindle section 6, so that when thus interengaged said spindle sections will rotate in unison.

As shown in Figs. 5, 6 and 8, the forward spindle section 5| and its rearward extension 52 are respectively provided with the transverse slots providing the wrench hold flats 6| and 62 whereby they may be relatively rotated, by suitably provided wrenches, with the interengaging screw threads 53 cooperating to cause the conical shoulders 63 of the rearward extension 52 to engage the correspondingly inclined conical socket G5 in the back end of the forward portion of the forward spindle section 5| to form the composite spindle section structure.

As shown in Fig. 5, the forward end of the bore 66 of the spindle section 5| is conically tapered toward the axially aligned tool receivin aperture 61 and affords a conical forward seat 68 for the longitudinally split chuck 69 through the bore 1|] of which the shank H of the tool, which as illustrated in Fig. 1 comprises the bur 12, extends.

Referring further to Fig. 5, the split chuck 69 is normally expanded to receive the tool shank and has its opposite ends formed conical and respectivel arranged to engage the conical seat 68 in the bore of the spindle section 5| and the conical seat 73 in the forward end of the follower 0r plunger 14 which is disposed for axial movement in the bore 66 and which is arranged to be forced forward to effect contraction of the chuck 59 by the axial adjustment of the chuck rod 15.

Said chuck rod 15 bears against the plunger 74 and is provided at its forward end with the screw threads 16 which engage the internally screw threaded forward end region 11 of the rearward extension 52 of the spindle 5| so that its rotation may effect axial movement of the chuck actuating plunger 74 to cause the engagement or release of the tool shank II by the chuck 69 depending upon the direction of rotation of said chuck rod.

The chuck rod 75 extends through the rearward extension 52 and rear spindle section 6 and has the squared terminal region 18 which extends through the correspondingly square aperture 19 in the rotatable thumb-nut l9, fitting snugly there-in but having freedom of relative axial movement therethrough when said thumb-nut is rotated to actuate the chuck 69 by cooperation of the screw threads 16 with the threaded forward end region of the extension 52.

As shown in Figs. 17 and 18, the thumb-nut I9 is provided with the circular recess 80 the inner plane *wall 8| of which is provided with a plurality of relatively intersecting conoidal recesses 82 which also intersect the walls 83 of the square aperture 19' in the thumb-nut IS, the apices of said cono'idal recesses being disposed in planes extending through the corners of the square aperture '19 and the axes of said recesses being located on-radii disposed away from the axis of the thumb-nut it at a distance somewhat less than the radius of a circle to which the flat walls 83 of the square aperture 19 are tangent.

From the foregoing, it will be obvious that when the terminal corners 84 of the chuck rod 15 engage the surfaces of the conoidal recesses 82 and further axial inward thrust of said chuck rod 15 is exerted, said corners will ride upon their re spective cooperative conoidal surfaces and thus tend to rotate the thumb-nut 19 until the flat walls 33 of the square aperture 19 register with the flats of the squareend region 18 of said chuck-rod l5 and thereby facilitate its free entrance therein. As a means of precaution and protection, the chuck-rod 15 is provided with the hemispheroidal knob 85 which forms a guard for the terminus of the squared end region, as is best illustrated in Fig. 16.

Referring now more particularly to the contraangle handpiece assembly illustrated in Fig. 14, the handhold comprising the ribbed andknurled sheath Bi; and its rearwardly extended ferrule 81 embracing-the spindle section 6., has the sheath attachment block 88 which is provided with the projectingpin 89 having the detent engaging notch 90 arranged to be removably engaged by the detent plunger 25 to retain the inner face 91 of said sheath attachment block 88 normally against the wrist-joint f'ram'el.

Assh'own in Fig. 14, the ferrule 81 is removably engaged with the rearward end region of the sheath 86 by the screw threads 92, and the forward end ofsaid sheath 86 has the collet 93 secured therein as by solder and to which the contra-elbow 94 'ofthe contra-angle head 95 of well known construction and carrying the bur 96, is removably attached by the screw threadsQl.

Rotatably extended through the sheath 86 and its ferrule 81 is the bur driving spindle 98 having the forwardly extended spindle stub 99 rotatably mounted in the collet 93 and having its opposite end regions respectively engaged withthe spindle 98 by the pin I and with the driving gear llll by the pin I02.

The inner or rear end of said bur driving spindle 9B is rotatably supported by the spindle bearing dog I03 which encircles said spindle 98 and is engaged thereon by the pin I04 and which has the rearwardly extending prongs I which are arranged to removably interengage with the forwardly extending prongs l2 of the rear spindle section 6.

Referring now to the right-angle handpiece assembly illustrated in Fig. 15, the handhold comprising the ribbed and knurled sheath I06 and its removably extended ferrule I01 embracing the spindle section 6, has the sheath attachment block I08 which is provided with the projecting pin I09 having the detent engaging notch H0 arranged to beremova bly engaged the detent plunger 25 to retain the inner face ill of said sheath attachment block Hi8 normally against thewrist-Iiointframe l. i

As "shown in Fig. 15, the ferrule It! is remov ably engaged with the rearward endregion oi the sheath H16 by the screw threads 4 l2, and the forward end of the sheath M6 has the collet H3, with forwardly extending neck H4, secured thereto as by solder and to which the right-angle head H5, of well known construction andcarry ing the bur 1 I6, is removably attached by the screw threads H1.

The bur driving spindle H8, having the forwardly extended spindle stubllt which is retatably mounted in the collet H3, is extended through the sheath IE6, and said spindle stub H9 has its opposite end regions respectively engaged with the spindle t It b the pin lit-and with the bevel driving gear I21 by the pin 122. i

The inner or rear'end of said bur driving spin dle 1 I8 is rotatably supported by the spindle bearin-g dog I23 which encircles said spindle H8 and is engaged therewith by the pin 124 and which has the rearwardly--' extending prongs 125 which are arranged to removably interengage with the forwardlyextending prongs 'l 2 of the rear spindle section-6. i 1

My invention is particularly advantageous in that the driving mechanism including the frame I and swivel post 2 may remain intact on a supporting engine arm, of well known construction, with the driving pulley 13 in connected relation with its driving cord-or belt, While the handpiece proper may be withdrawn and replaced, or the contra-angle handpiece shown in Fig. 14 or the right-angle handpiece shown in Fig. 15 maybe interchangeably substituted for the straight handpiece shown in Figs. 1, 3 and 5 with equal facility. 1 do not desire to limit my invention to the precise details of construction and arrangement as herein-set forth, as it is obvious that various modifications may bemade therein without departing fromthe essential features of my invention as defined in the appended claims.

Having thus described my invention, I claim f1. it dental engine handpiece comprising a wrist-jointsupport, a sheath removably carried by said support, means arranged to yieldingly engage said sheath with said support, a tool actuating spindle having relatively separable complerne'ntary sections operatively connected in slipjoint relation to rotate as a unit, and respectively mountedindependently in hearings in said sheath and in said supportand arranged to be relatively disconnected "by the axial withdrawal of said sheath'frjom said support, tool chucking means adjustable to effect clamping and releasing of a tool, and including a chuck rod extended through andbeyond saidspindle and adjustably engaged therewith, and means exterior to said spindle arranged to actuate said tool chucking means to effect grip or release of said tool.

2. A dental engine handpiece comprising a wrist-joint support, a sheath removably carried by said support, means arranged to yieldingly engage said sheath with said support, a tool actuating spindle having relatively separable complementary sections operatively connected in slipjoint relation to rotate as a unit, and respectively mounted to rotate in said sheath and in said support and arranged to be relatively disconnected by the axial withdrawal of said sheath from said support, tool chucking means mounted asasnsc in said spindle adjustable to clamp and release a tool, and including a chuck rod in screw threaded engagement with the spindle and extended through and beyond the rear end of said spindle, and a thumb nut mounted for rotation on said spindle and arranged to relatively rotate said rod therein to effect grip or release of said tool.

3. A dental engine handpiece comprising a wrist-joint support, a sheath removably engaged with said support, means arranged to yieldingly engage said sheath in rigid relation with said support, a, tool actuating spindle having relatively separable complementary axially aligned sections operatively connected in slip-joint relation and respectively mounted to rotate as a unit in said sheath and in said support and arranged to be relatively disconnected by the axial withdrawal of said sheath from said support, and tool clamping means mounted in said spindle adjustable to clamp and release a tool, and including a chuckrod in screw threaded engagement with the forwardly disposed spindle section, and extended rearwardly beyond the rearwardly disposed spindle section and affording means by which it may be rotated with respect to said spindle and thererespectively mounted to rotate as a unit in said sheath and in said support and arranged to be relatively disconnected by the axial withdrawal of said sheath from said support, and tool clamping means mounted in said spindle adjustable to clamp and release a tool, and including achuckrod in screw threaded engagement with the forwardly disposed spindle section, and extended rearwardly beyond the rearwardly disposed spin dle section and affording means including a polygonal terminal region by which it may be rotated, and a thumb-nut having a polygonal aperture slid-ably fitted to said chuck-rod for axial withdrawal and mounted forrelative rotation on said spindle but restrained from axial relative movement thereon.

5. A dent-a1 engine handpiece comprising a support, a sheath removably engaged with said support and having an end thrust bearing, means adjustable to vary the length of said sheath to effect takeup on said bearing, a tool actuating spindle terminating in said bearing and having relatively separable complementarysections operatively engaged to concurrently rotate and respectively mounted for rotation in said support and in said sheath and arranged to be relatively separated by axial withdrawal of said sheath from said support, tool chucking means including a split chuck and follower therefor mounted in the forward section of said spindle, adjustable to engage and release an operative tool, a chuckrod extended through said spindle in threaded engagement therewith, rotatable to adjust said chuck, and having a polygonal terminal region protruding beyond the rear end of said spindle, and a thumb-nut rotatably mounted on said spindle and having a polygonal aperture through which said chuck-rod extends for relative axial movement.

6. A dental engine handpiece comprising a support, a sheath removably engaged with said support by a snap detent connection and having an end thrust bearing, a tool actuating spindle terminating in said bearing and having separable complementary sections operatively engaged in relatively separable relation to concurrently rotate and respectively mounted for rotation in said support and in said sheath and arranged to be separated by axial withdrawal of said sheath from said support, tool chucking means including a contractable and expandable chuck and cooperative follower therefor adjustable to engage and release an operative tool, a chuckrod extended through said spindle in threaded engagement with the forward section thereof, rotatable to adjust said chuck with respect to said tool and having its terminal region shaped to form a key projecting beyond the rear end of the rear section of said spindle, and a thumb nut rotatably mounted on the rear section of said spindle and having an aperture formed to engage said key and arranged to effect rotation of said chuck-rod but to permit its axial withdrawal therefrom upon separation of said spindle sections.

7. A dental engine handpiece comprising chuck actuating mechanism which includes a chuck actuating rod mounted for axial adjustment by rotation and having a polygonal terminal region, a relatively removable thumb-nut having a polygonal aperture through which said polygonal terminal region may be removably extended, and having a plurality of relatively intersecting recesses providing curved walls which serve as guides for directing said terminal region into said aperture.

' ROBERT C. ANGELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 369,865 Firth et a1 Jan. 29, 1899 434,697 Browne Aug. 19, 1890 869,563 Hardy Oct. 29, 1907 1,632,991 Booth June 21, 1927 1,835,961 Pieper Dec. 8, 1931 1,839,289 Angell Jan. 5, 1932 

